Presentation Information
[11a-A33-4]Observation of Exciton-Anion Fusion in Triazine Derivatives
〇(B)Ryosuke Hanashima1, Manato Tateno2, Renjiro Shibuya2, Seita Kyogoku2, Shintaro Mitsui2, Takeshi Okada3, Nobumichi Arai3, Hisao Ishii2,4,5, Hirohiko Fukagawa2,4,5 (1.F.Eng. Chiba Univ., 2.GSSE Chiba Univ., 3.Tosoh Corporation, 4.CFS Chiba Univ., 5.MCRC Chiba Unniv)
Keywords:
photoelectron spectroscopy,organic semiconductor,spontaneous orientation polarization
Biphotonic electron emission (BEE) in organic semiconductors occurs below the ionization energy. While BEE has been mainly attributed to Exciton–Exciton Fusion (EEF), Exciton–Anion Fusion (EAF) induced by Spontaneous Orientation Polarization (SOP) has been proposed, where anion accumulation occurs. However, its contribution has been discussed based on energetic considerations, and direct experimental verification has been lacking. We investigate EAF by controlling SOP and examining the correlation with emission intensity. Using triazine derivatives with opposite polarization, we compare systems with positive and negative surface polarization charge. Systems involving both EEF and EAF exhibit strong emission with broader spectral width, whereas systems with only EEF show much weaker emission with narrower spectra. These results indicate that the contribution of EEF is minor and that BEE predominantly originates from EAF, providing direct experimental support for the EAF mechanism.